In conventional audiometric testing, a test recipient is required to be assessed by a trained test provider, typically a healthcare professional, using an expensive and complicated piece of analog test equipment. The analog test equipment consists of a calibrated system comprising an analog headset and an analog tone generator capable of generating pure tone signals at several test frequencies and volume levels. The test frequencies and volume levels are as prescribed by relevant test standards in the jurisdiction in which the test is being conducted.
The entire analog system must be calibrated as a whole and can only be certified for use at the selected calibration test frequencies. This requires both the headset and tone generator to be sent off-site to a certified calibration lab, taking them out of service for a prolonged period of time, and limits the testing performed with the system to only the prescribed frequencies. There is therefore no way to test at intermediate frequencies in order to better discriminate a region of hearing loss. In addition, the calibration of the analog equipment is often only performed at one loudness level, potentially leading to the equipment producing inaccurate loudness levels at other volumes. There is no means to periodically check the calibration of a particular headset, nor is there a means to compensate for a drift in calibration in between offsite re-calibrations. It is not possible to interchange headsets with a pre-calibrated tone generator in the event that a particular headset becomes defective. The test must be performed and interpreted by a healthcare professional in order to identify regions of hearing loss and to specify an appropriate hearing aid device or other appropriate course of action. There is no way of administering a hearing self-test, particularly in the home, and no means of sharing the self-test data with trained professionals. There is currently no way to emulate the effect of a hearing aid for the test recipient, especially in typical real world environments, and no way to emulate for a third party (eg: spouse or partner of the test recipient) the way in which sounds are perceived by the test recipient. There is currently no way to adjust the audio output of digital audio emitting devices (eg: cell phones, MP3 players, iPod's, computers, etc.) to improve the listening experience of a particular hearing impaired listener.
In order to address some or all of the foregoing problems in the art, there remains a need for an improved audiometric test apparatus, improved audiometric test methods, and improved methods of calibrating audio emitting devices to account for deficiencies in hearing.